1. Field of Invention
This invention relates to packaging containers for electronic components. In particular, this invention relates to a packaging container for integrated circuits, wherein the composition of the cover for that packaging container includes a desiccating material and an electrostatic charge dissipating and/or anti-static material. In addition, this invention relates to a packaging container for integrated circuits, wherein the composition of the cover for that packaging container includes a desiccating material, an electrostatic charge dissipating and/or anti-static material and a humidity indicating system.
2. Prior Art
Electronic components, such as integrated circuits (xe2x80x9cICxe2x80x9d), are conventionally shipped from a factory to the user in large quantities. To protect these ICs during transportation, they are generally secured in special trays. Sections CO-027-CO-032 and CO-034, and sections CS-002-CS-008 of JEDEC publication, JEP95, contain outlines and specifications for standardized thin and thick matrix trays for various IC types.
Plastic integrated circuit devices are susceptible to moisture due to the permeable nature of their plastic components. It is well known that ICs, which have been contaminated by high levels of moisture, may not be useful. Mechanical failure of such moisture contaminated ICs often leads to the subsequent failure of the device which contains the IC due to thermal and mechanical stress. Accordingly, exposure of ICs to moisture should be limited.
For specialized types of packaging for ICs, refer to U.S. Pat. No. 4,971,196, U.S. Pat. No. 5,095,626, U.S. Pat. No. 5,293,996 and U.S. Pat. No. 5,295,297. Each of the packaging containers disclosed by these patents incorporates a moisture indicator device into the packaging container, which device is secured to the inside surface of the container. See specifically FIGS. 7 and 10 of these patents.
Specifically, U.S. Pat. No. 5,293,996 discloses a packaging container for integrated circuits containing an observation window. The container is divided into three sections, wherein one of those sections contains a compartment (11) housing a humidity indicator device (16). The humidity indicator device (16) is preferably a humidity indicator card. As best understood the card is merely placed within the compartment for viewing. The composition of the packaging material of the compartment containing the humidity indicator card is a transparent plastic which permits the moisture indicator card to be viewed from outside of the packaging container.
U.S. Pat. No. 5,318,181 discloses compartmentalized humidity sensing indicators. These humidity sensing indicators are produced on a tape reel and are secured to the inside surface of a continuous strip of humidity indicators.
U.S. Pat. No. 2,446,361 discloses a humidity indicating moisture adsorbent product secured to packaged goods. The product comprises a container (A) onto which is secured a receptacle (B). Contained within the receptacle (B) is a desiccant (C). The receptacle (B) is transparent and may be formed from plastic materials. It is screwed into a threaded mounting apparatus which is also secured to the container. It is comprised of a cylindrical wall (16), closed top (17) and a perforated bottom (18). The receptacle (B) is secured in place to the package by a collar (20) and a locking ring (22) containing threads (24, 28). The receptacle (B) may be screwed in place using one of two different designs as disclosed in FIGS. 2 and 3 of the patent.
See also U.S. Pat. No. 5,238,648 which discloses a view port in packaging through which can be viewed an oxygen indicator device.
In addition to their susceptibility to moisture, ICs can also be damaged by static electricity. Therefore, it is important that the packaging for such electronic components also be resistant to electrostatic charge. This resistance should be present in the tray on which the ICs are stored as well as in the moisture-proof bag in which the tray is shipped. A laminated packaging system for ICs, which is resistant to static charge is disclosed in U.S. Pat. No. 5,136,827 and U.S. Pat. No. 4,568,416.
It is well known that electronic components are also sensitive to particles and dust. Therefore, manufacturing and assembly of electronic devices is performed in clean rooms of class 100-10. 
Current packaging products which are used to ship integrated circuits still exhibit deficiencies, including limitations caused by the composition of the packaging material. Conventionally, the packaging material used for shipping integrated circuits is opaque, thus preventing easy inspection of conventional humidity indicator cards which are contained within the packaging unless the packaging material is breached. In certain new packaging materials, the composition of the surface of the packaging is different from the composition of the remaining portion of the packaging that is adjacent to the humidity indicator so that the humidity indicator card can be viewed from outside of the packaging.
In addition, the method for attachment of the humidity indicator device to the inside surface of the packaging material is often not practical.
Further, packaging products for shipping integrated circuits often must include desiccant products because of the sensitivity of the integrated circuits to moisture. Several plastic materials which may be used for packaging have been produced which have incorporated moisture absorbing products, such as desiccating materials, into their structure. For example, U.S. Pat. No. 5,911,937 discloses a product made from 30 to 80 percent desiccant, 20 to 40 percent thermoplastic and 5 to 20 percent of a channeling agent, wherein the channeling agent includes any hydrophillic material which is miscible with a polymer-based matrix upon melt mixing to form the channeled structure. These compounds preferably include polar compounds having at least several hydroxy groups, such as polyglycols. The desiccants that can be incorporated within this plastic material include anhydrous salts, molecular sieves, silica gels, clays and starches. See also WO 96/33108.
A number of other plastic materials have been produced into which desiccating products have been incorporated. For example, U.S. Pat. No. 5,078,909 discloses a moisture absorbent product comprising 100 parts by weight of a thermoplastic resin and 5 to 400 parts of a desiccant. U.S. Pat. No. 5,432,214 discloses a plastic product containing a desiccant comprising 50-80% of a thermoplastic or thermosetting product, 20-50% of a dehydrating agent, 2-8% of an elastomer and 1-4% fibers. EP 432,438 discloses a desiccating plastic product comprising 100 parts of an absorbent particles mixed with 10 to 50 parts of a plastic particle and a reinforcing fiber. U.S. Pat. No. 4,061,807 discloses a desiccating product containing 60 to 95 parts of absorbent granules mixed with 50 to 40 parts of a thermoplastic particles. U.S. Pat. No. 5,591,379 discloses a coating or adhesive material which is placed on packaging for micro-electronic devices. A desiccant product is dispersed in the binder to form the coating or adhesive. The binder may include a number of polymers.
U.S. Pat. No. 4,013,566 discloses a desiccant combined with a thermoset material. U.S. Pat. No. 4,665,050 discloses a desiccant that is embedded in a plastic without melting the plastic. U.S. Pat. No. 3,245,946 discloses a desiccant incorporated into a rubber product for absorbing the moisture contained within the rubber product. U.S. Pat. Nos. 4,792,484 and 4,407,897 disclose the use of EVOH copolymers with particular products including conventional desiccant materials. See also U.S. Pat. Nos. 5,496,397 and 5,401,706.
U.S. Pat. No. 5,702,508 discloses a moisture removing device comprising a ceramic shell with a plurality of parallel openings. The openings form elongated structure surfaces adapted to be in contact with moisture laden air moving through the openings. The surfaces have desiccant capabilities.
U.S. Pat. No. 4,665,050 discloses a self-supporting structure wherein 1 to 7 percent polymer is mixed with absorbent particles to form a sorbent product. U.S. Pat. No. 4,427,992 discloses a desiccant for semi-conductor products which may be applied in liquid form and consist of ethyl-alcohol, ethyl-acetate water and a source of boron, alumina or phosphorous and organic silane.
Finally, DE 4,013,799 discloses an insert for containers, particularly for medicines and semi-luxury consumer goods, wherein a granular drying agent is embedded in plastic.
As referenced above, integrated circuits are particularly susceptible to moisture and can also be damaged by static electricity. Further, these components are particularly sensitive to dust. Accordingly, in the prior art integrated circuits have been prepared for shipping using a complicated and expensive process which includes at least the following process steps:
a) inserting the integrated circuits into trays;
b) baking the integrated circuits dry on the trays;
c) stacking the trays on top of each other;
d) covering the tray stack with a tray cover;
e) inserting the covered tray stack in a moisture and water-proof bag;
f) inserting desiccant bags into the moisture-proof bag;
g) placing a humidity indicator card into the bag; and
h) sealing the bag.
An alternative procedure included at least the following steps:
a) baking the integrated circuits dry separately from the packing trays;
b) inserting the dried integrated circuits into the trays;
c) stacking the trays on top of each other;
d) covering the tray stack with a tray cover;
e) inserting the covered tray stack in a moisture and water-proof bag;
f) inserting desiccant bags into the moisture-proof bag;
g) placing a humidity indicator card into the bag; and
h) sealing the bag.
In addition to the fact that this process is complicated, labor-intensive and time-intensive, the integrated circuits are protected from moisture only after the moisture-proof bag is sealed. Integrated circuits can still absorb moisture at any time from their original baking until the sealing of the bag.
Another disadvantage of the prior art processes is that the integrated circuits are also exposed to dust for a greater period of time. This dust may even include generated dust from the desiccant bags themselves.
Accordingly, it is an object of this invention to prepare a packaging container for electronic components which reduces the level of moisture within the container during shipment.
It is still further object of the invention to disclose a packaging container for electronic components, wherein the composition includes a desiccant product.
It is still further object of the invention to disclose a packaging container for electronic components which incorporates an electrostatic charge dissipating and/or anti-static material into the composition of the packaging container.
It is still further object of the invention to disclose a packaging container for integrated circuits which produces less dust and other particulate matter during packaging and shipment.
It is still further object of the invention to utilize a process for loading electronic components that has fewer steps and reduces the time and expense of the packaging process.
These and other objects and features of the present invention will become apparent to those skilled in art from a consideration of the following detailed description, drawings and claims. The description along with the accompanying drawings provides a selected example of the construction of the device and its process of manufacturing to illustrate the invention.
In accordance with the present invention there is provided a packaging container for electronic components, which components are sensitive to humidity, which includes
trays for holding the electronic components, and
a tray cover, whose composition comprises a plastic material, an electrostatic charge dissipating and/or anti-static material and a desiccant for absorbing moisture contained or penetrating into the packaging container.
Alternatively, the present invention provides a packaging container for electronic components, which components are sensitive to humidity, which includes
trays for holding electronic components,
a tray cover, whose composition comprises a plastic material, an electrostatic charge dissipating and/or anti-static material and a desiccant for absorbing moisture contained or penetrating into the packaging container during shipment, and
a humidity indicating system secured to the tray cover for determining the humidity level within the packaging container.
The present invention further includes the packaging container discussed above placed within a moisture-proof barrier bag for shipment.
The present invention further includes a process for the filling and shipping of a packaging container with integrated circuits comprising
introducing integrated circuits into shipping trays;
baking the integrated circuits while in the trays to remove moisture;
securing a tray cover onto a stack of the baked trays, wherein the tray cover is comprised of a plastic material, an electrostatic charge dissipating and/or anti-static material and a desiccant for absorbing moisture contained or penetrating into the packaging container; and
placing the covered tray stack containing integrated circuits within a moisture-proof barrier bag.
Alternatively, the present invention includes a process for the filling and shipping of a packaging container with the integrated circuits comprising
introducing dry, baked integrated circuits into shipping trays;
securing a tray cover onto a stack of the trays, wherein the tray cover is comprised of a plastic material, an electrostatic charge dissipating and/or anti-static material and a desiccant for absorbing moisture contained or penetrating into the packaging container; and
placing the covered tray stack containing integrated circuits within a moisture-proof barrier bag.